Two-zone pump



July 4, 1950 Fil`ed Oct. 11, 1946 T. P. HOFFER TWO-ZONE PUMP Aj M 5Sheets-Sheet 1 ATTORN EYS T. P. HOFFER July 4,. 1950 TWO-ZONE PUMP 5Sheets-Sheet 4 Filad 001' TEMLE L? HOFF-'ER INVENTOR.

MTORNEYS July 4,1950 T. P. HOFFER TwozoNE PUMP Filed oct. 11. 194ePatented July 4, 1950 TWO-ZONE PUMP Temple P. Hoffer, Dallas, Tex.,assignor to Otis Pressure Control, Inc., Dallas, Tex., a corporation ofDelaware Application October 11, 1946, Serial No. 702,769

Claims.

This invention relates in general to pumps of the type used generally inpumping fluid from deep wells and has for its general object theprovision of such a pump which will eiciently pump fluid simultaneouslyfrom two different zones of production in a well and move such fluidtoward the upper end of the well without intermingling of the productionfrom the two zones.

More specifically itis an object of the present invention to providesuch a structure which will be simple both in its construction and inits operation and will vary from the conventional construction of deepwell pumps by the least possible amount.

, Another object of this invention is to provide such a structure inwhich that portion of the pumping mechanism which pumps from the lowerzone of production 4will not be subject to so-called gas locking in theevent that the iluid being pumped contains substantial amounts of gas.

Another object of this invention is to provide such a. structure inwhich the discharge from the portion of the mechanism which pumps fromthe lower zone will be through an annular space surrounding that portionof the mechanism which pumps from the upper zone.

Another object of this invention is to provide a modified form ofstructure in which the pumping mechanism for pumping from the upper zonemay be located closely adjacent or within the zone of production itselfso that it may pump eiiiciently from so-called low iiuid level wells.

Another object of this invention is to provide a modified form of such amechanism in which the space about the pumping assembly may be packedoff immediately above the upper producing zone and the pumping mechanismfor pumping from the upper producing zone located above such.paek 01T soas to reduce. the amount of structure necessary to provide for thepassage of production from the lower zone through the pack oi.

Another object of this invention is to provide a, structure in which thenecessary packing between the upper and lower cylinders, and thestanding valve for the upper cylinder may be readily removed andinserted with the pump actuating rod.

Still another object is to provide such a structure in which the lowerpumping cylinder and the standing valve therefore may likewise beremoved and inserted with the pumping rod.

Yet another object is to provide a two zone 2 pump which will permiteither zone to flow under its own pressure while pumping the other.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings wherein are set forth by way of illustration and example, andnot by way of limitation, certain embodiments of this invention.

In the drawing: Fig. 1 is a view principally in longitudinal crosssection illustrating the upper end portion of a pump constructed inaccordance with this in-" Fig. 4 is a view partly in longitudinal crosssection and partly in side elevation showing a' continuation of thelower portion of Fig. 3.

Fig. 5 is a viewsimilar to Fig. 4 and showing a continuation of thelower end portion thereof. Fig. 6 is a view similar to Fig. 5 andshowing the lowermost end portion of the pumping mech- -anism.

Figs. '7, 8 and 9 are views similar to and corresponding respectively toFigs. 1, 2 and 3 but showing a modied form of uper end construction ofthe pumping mechanism in which the upper pumping cylinder is locatedbelow the packer which packs off between the pumping mechanism and theupper producing zone, for use in low uid level wells, instead of beingabove such packer as shown in Figs. 1, 2 and 3 intended for high fluidlevel wells.

Figs. 10, 11, and 12 are views similar to and corresponding respectivelyto Figs. 4, 5 and 6 but showing a modified lower end construction forthe pumping mechanism in which the lower pumping cylinder is notremovable with the pumping rod, so that it may be made of largercapacity than when it is made removable through Y the upper cylinder asshown in Figs. 4, 5 and 6.

Fig. 13 is a schematic view illustrating the mechanism shown in Figs. 1to 6 inclusive.

Fig. 14 is a detail of a portion of the mechanism shown in Figs. 3 and 4illustrating the stuffing box for the upper zone pump secured to thepolish rod in position to be lowered into the well tubing.

Referring now more in detail to the drawing and particularly to Figs. 1to 6, inclusive thereof, the pumping mechanism is illustrated as beinglocated within a well casing I having openings 2 therethrough for thepurpose of admitting a flow of iiuid from an upper producing formation.and openings 3 therethrough for the purpose of admitting a flow of iluidfrom a. lower producing formation.

The non-moving portions of the pumping mechanism are carried on thelower end of the customary well tubing 4 and connected thereto by meansof a, special coupling or tting 5 which is threaded at 6 to the lowerend of the tubing and is provided with internal threads at 1 forreceiving the upper end of the upper cylinder jacket 8 of the pump. Thetting 5 also provides a downwardly facing shoulder 3 adapted to clampagainst and hold in place the upper cylinder liner I0. On reference toFig. 2 it will be seen that the lower end of the jacket -8 is threadedlyreceived at II by the iltting I2 and that this iitting I2 likewiseprovides an upwardly facing shoulder I3 which abuts the lower end oi theupper cylinder liner I so that the liner I0 is clamped in place betweenthe shoulders 3 and I3. l

The fitting I2 is provided with external threads I adapted to receivethe upper end of the upper packer sleeve I8. This upper packer sleeve I8is internally threaded at I1v to receive the packer .mandrel I8 and thelower end of this mandrel is `ethreaded into the lower packer sleeve I3as shown at 20. Intermediate its ends the mandrel I8 is provided with anenlargement 2I against which are abutted the composite ring clamps 22and 23 respectively which carry the upper and lower packer cups 24 and25. Each of these cups is provided with a lip, the upper of whichextends upwardly as shown at 28 and the lower of which extendsdownwardly as shown at 21 and both of which are normally of a sizeslightly larger than the interior of the casing so that they will bearlightly against the inner surface of the casing even when not subjectedto uid pressure. It will be seen that pressure from above encounteringthe upper packer 24 will tend to spread the lip 28 outwardly and urge itinto more iirm engagement with the casing and likewise that pressurefrom below will tend to urge the lip 21 more firmly into engagement withthe casing.

The packer sleeve I8 is provided with a downwardly facing shoulderexternally of the mandrel I8 and this shoulder is in turn provided witha lip 28 adapted when the sleeve is moved downwardly to engage the lip28 on the packer element 24 and draw it inwardly away from the casing sothat it may be moved 4readily through the casing. Likewise the packersleeve I3 is provided with a lip 28a adapted to engage the lip 21 on thelower packer element 25 when the assembly is being moved upwardlythrough the casins The lower packer sleeve I3 is threaded at 23 to thecross over tting 30 which has lateral openings 3l therethrough to permitow from the upper producing zone through the openings 2 to pass inwardlythrough the openings 3| and into.

wardly from the upper end of the lower` cylinder as will likewise bepresently described. These passageways 32 communicate at their upperends with an annular space between the interior of the packer mandrel I8and a thin walled tube 33. The lower end of this tube 33 is seatedwithin the cross over fitting on an upwardly facing shoulder 34 as shownin Fig. 3 and the tube extends upwardly partly through the upper packersleeve I6 within which itis sealed by means of the packing 35 held inplace by the gland nut 38. The annular space 31 thus formed between themandrel I8 and the tube 33 provides a conduit for the upward conductionof uid emerging from the passageways 32 in the cross over fitting 30. Atthe upper end of this annular space 31 communication is had throughports 38 in the upper packer sleeve I8 between the annular space 31 andthe annular space 33 between the casing I and the tubing 4. Thus ow fromthe lower pumping mechanism is conducted to the surface of the groundthrough the annular space 33, after emerging from the annular space 31by which it is conducted through the packer.

The lower end of the cross over flow connection 30 is provided withexterior threads 40 which receive the swedge fitting 4I, to the lowerreduced end of which is threaded as at 42 a. coupling 43 receiving thesection of tubing 44 which extends downwardly to the lower producingzone to be pumped. At an appropriate place on this tubing 44 there isprovided a packer 45 which may be of any suitable conventionalconstruction such as for example the packer formed by the elements 24and 25 previously described. To the lower end of this tubing 44 isthreaded a special coupling 45a which is internally threaded at itslower end to receive the upper end of the tubular guide 46 for the lowerpumping cylinder.

'Ihe cross over fitting 30 is also interiorly threaded at its lower endto receive the tubular latching member 41. This tubular member 41extends downwardly from the cross over tting 30 and is split adjacentits lower end into a plurality of spring ngers 48 hav/ing recesses 43therein for a purpose presently to be described. Just below the recesses43 are projections 53 which normally extend inwardly in a radialdirection to provide an eii'ective internal diameter less than that ofthe main portion of the tubular body 41. The extreme lower ends of thesengers are inwardly beveled at 5I so that they may be spread apartslightly by an object of slightly larger diameter than the effectivediameter between the vfmechanism just described are carried onconventional pumping or sucker rods 52 which may be reciprocated by theusual means at the top of the well or by any other means for applyingpower to them either at the top of the well or adjacent the pump itself.

To the lower end of the string of sucker rods is secured in thisinstance the upper traveling valve 53 consisting of a cage 54 in whichis carried a ball valve 55 adapted to seat against a valve seat 56carried on the upper end of the fitting 51. To the lower end of thefitting 51 is secured the polished tubular member 58 which forms thebody of the upper pump plunger and is adapted to closely but slidingly twithin the cylinder liner I0. The lower end of this tubular member isconnected by a fitting 53 with a special iltting having radial owpassages 8| therethrough so that flow of uid may take place unwardlythrough the pump liner I 8, inwardly thzough the openings 8|, thenceupwardly through the fitting 89, hollow plunger body 88 and fitting 51to pass through the traveling valve 66 and out through the openings inthe cage 84 into the space within the tubing 4 around the sucker rods52, and thence to the surface of the ground through the tubing 4.

The lower end of the fitting 80 is threaded to a rod 82 which in thisinstance is a solid polished rod that extends down through the tubularmember 83 and the standing valve at the lower end thereof. This standingvalve consists of an annular valve body 63 provided with a conical orspherical seat portion 84 around its upper end, an upstanding portionprovided by the split fingers 65 extending above the seat portion andterminating in the lateral lugs 68. Intermediate its ends this body isprovided with a lateral projection having a reduced portion adapted toreceive packing 81 to form a seal about the body within the tubularmember 83. Extending longitudinally through this lateral projection tobypass the packing 61 are flow passages 88, which emerge through theseat 64. This body 88 may be made in any suitable manner such as bymaking the parts which are inwardly and outwardly respectively from thepassages 88 as separate tubular members, slipping them together,inserting spacers between them to provide passages 88, securing theparts together, and subsequently finishing the seat 84 on the compositebody. Slidably carried about the upstanding parts 65 and adapted to seatagainst the seat 84 when in its lowermost position is an annular or ringvalve 69. This ring valve is placed over the parts 65 by forcing themtogether to decrease their overall diameter at their upper ends beforethe rod 62 is put through the body. These parts 86 may then expand toadmit rod 82 and lugs 66 will serve as upper limit stops for the valvering 89. It will be seen that this arrangement permits flow upwardlyfrom the lateral openings 2 in the casing and 8l in the cross overfitting through the passageways 88 in the valve body 83 and into thetubular member 33 and thence to the upper pumping cylinder, but thatflow downwardly cannot take place along this path because the ring valve69 will seat on the seat 64 and prevent it.

The valve body 83 is of an internal diameter to snugly but slidablyengage the polished rod 62, and it is threaded at its lower end toreceive a coupling 10 which carries a nipple 1l on which is mountedpacking 12 to seal the nipple within the latching tube 41. Secured tothe lower end of this nipple is a stuffing box element 19 having packing14 therein to provide a seal about the polished rod 62. The lower end ofthis fitting 13 is threaded to an inner latching member 'l5 which in amanner similar to the tubular latching member 41 is of tubular formationat its upper end and is split to form flexible fingers 16 adjacent itslower end. These flexible fingers 18 have outwardly extendingprojections 11 thereon adapted to fit in the recesses 49 and downwardlyand inwardly inclined lower end projections 18 below the projections 11.f

Below the latching mechanism just described the polished rod is threadedinto a special coupling 19 having an outwardly flared upper end 88adapted when moved upwardly by an upward movement of the polished rod toengage with the downwardly and inwardly inclined projections 18 and drawthe latching fingers 16 inwardly toward each other so as to make themreadily removable from the latching fingers 48. When the device is beingrun into a well, a shear screw is employed in the threaded openingsshown in one of the projections 18 and the flared upper end 89 ofcoupling 19, to hold the flared end portion 89 in engagement with theprojections 18 until such time as the packing arrangement and upperstanding valve is moved into its correct position as indicated in thedrawing. This is shown in Fig. 14 where 80a designates the shear screw.In this connection it is noted that the shoulder on the lower side ofthe projections 11 and that at the lower extremity of the notchedportion 49 is a square shoulder so that the engagement of these partspositively limits downward movement of the packing arrangement and thestanding valve unit, whereas, the surfaces on the upper sides of theprojections 11 are inclined so that upon'forcible upward movement thefingers 18 will be moved inwardly to permit upward movement of thepacking and standing valve assembly.

To the lower extremity of the special fitting 19 is secured anadditional length of sucker rod 8| which is connected by means of aconnector l2 at its lower end with the pump rod 8l. The pump rod 83carries at its lower end a hollow pump plunger consisting oi the cage 84having radially opening passages therethrough as shown at 85, thetubular plunger body 86, and the traveling valve cage 81 with thetraveling valve 88 theiein at the lower end of the body 88. The body 86is adapted to fit Slidably but snugly within the lower pumping cylinder89 that carries the standing valve cage 98, standing valve 9| and thestanding valve seat 92 at its lower end. At its upper end this lowerpumping cylinder is con-l nected to a pack ofi arrangement consisting ofa fitting 93 secured to a mandrel 94 carrying packing rings 95. Thismandrel is of such size that flow may take place upwardly through theannular space between it and the pump rod 8l. A bumper cage 96 issecured to the upper end of the mandrel 94 and has radial passages 91therethrough so that iiuid flowing from the lower pumping cylinder upthrough the annular space within the mandrel 94 may pass out through theopenings 91 and into the annular space between the tubing 44 and thesucker rod 8|.

f It will be seen that when the cage 84 is pulled upwardly by upwardmovement of the sucker rods the shoulder at its upper end will engagebeneath the fitting 93 and pull this fitting together with the lowerpumping cylinder 89 and the standing valve at the lower end thereofupwardly out of the well. When being run in, it will be seen that theshoulder at the lower end of the fitting 82 may be made to engage withthe upper end of the cage 96 to force the packing arrangement at theupper end of the lower pumping cylinder together with the lower pumpingcylinder itself and the lower standing valve into operative position.

The pumping structure just described is provided with packings above andbelow the openings 2 in the casing and the openings 3l in the cross overfitting, which openings supply fluid to the upper pumping cylinder.Fluid from the lower pumping cylinder flows upwardly through thestanding valve at the lower end of the lower pumping cylinder, thencethrough the traveling valve and hollow plunger in the lower pumpingcylinder, thence upwardly through the passages 32 in the cross overfitting, and throughl the annular space 31 and passages 38 into theannulus 89 within the casing and about the tubing above the pump. Flowto the upper pumping cylinder takes place through the passages 68 in thestanding valve, upwardly through the tubular member 33 and into theupper pumping cylinder 8, thence through the upper hollow plunger andtraveling valve and the openings 54 into the annulus within the tubing 4and about the sucker rods 52, and thence to the surface.

The pump just described is intended for use in a well in which theproduction pumped by the upper pumping cylinders is of the so-calledhigh fiuid level type in which there is sufficient pressure within theformation to raise the fluid substantially above the openings 2 throughwhich it flows into the casing. This arrangement makes it possible forthe flow from the lower pumping cylinder after being conducted throughthe cross over fitting 30, to flow a relatively short distance throughthe packer mandrel I8 and thence into the casing annulus 39 and on tothe surface of the ground. This avoids the necessity for a structure forconducting this flow to the upper end of the upperpumping cylinderbefore emptying it into the casing annulus, and inasmuch as the pressurewithin the formation is assumed to be sufficient to force the fluidupwardly through the tubular member 33 and into the relatively highupper pumping cylinder 8 this arrangement will work very satisfactorily.As will be presently described, a slightly different arrangement isprovided as shown in Figs. 7, 8 and 9 for use in those cases in whichthe fluid level produced from the upper formation is not high enough topermit the use of this structure.

It will be seen furthermore that the packing 14 which surrounds thepolished rod between the two pumping cylinders, the upper standingvalve, the lower pumping cylinder and the lower standing valve, can allbe either inserted or removed or both with the sucker rods, thusavoiding the necessity of pulling the tubing for the replacement of anyof these elements. It is noted for example that not only is it possibleto replace a lower worn pumping cylinder but it is also pos- 'sible toreplace a lower cylinder with a cylinder of different size in the eventthat becomes desirable.

It is further noted that by virtue of the fitting .l

19 and the shear screw used lin securing this fitting to the projections18 while the assembly is being run into a well, it is possible both tohold the portion of the latching mechanism on the lower end of thepacking assembly in inactive position, and to pull the packing assemblyand the upper standing valve into seated position without any danger ofinjuring them such as might occur if they were pushed into seatedposition. As soon as they have been seated the shear screw can be brokenand the parts will be prop- `erly positioned, as illustrated, by meansof the engagement between the parts on the latching fingers 48 and 16.In this connection it is noted that the fingers 48 are made in thisfashion rather than as a complete annular member all the way to thelower end because of the possibility that the lower pumping cylindermight be of an outer diameter too large to pass between the inwardlyextending projections 50 unless these projections could move apart.

1 It is further to be noted that the flow from the lower pumpingcylinder passes upwardly through the lower plunger and traveling valveand up through and out of the upper end of this cylinder and thus thatit is unnecessary to provide a separate conduit outside of this cylinderfor conducting this ow upwardly therefrom.

Referring now to Figs. '7, 8 and 9 there is illustrated a somewhatmodified form of arrangement for the upper portion of the pumpingmechanism. In this instance a coupling |0| is provided to which theupper end of the upper packer sleeve I6 is secured, and the coupling |0|is secured directly to the lower end of the tubing. The packer structureneed not be described in detail as it is identical with that heretoforedescribed both in structure and in operation, although it differs inlocation in that it is located substantially above the upper pumpingcylinder. Thus, the lower packer sleeve I9 instead of being connecteddirectly to the cross over fitting 30 is connected to a special fitting|02 having longitudinal passageways |03 therethrough. The tubular member33 is seated in a counterbored portion in the upper end of the fitting|02 in identically the same manner that in the previous illustration itwas seated within a counterbored portion in the upper end of the crossover fitting 30. Welded at |04 to the exterior of the lower end portionof the tting |02 is a sleeve |05 which extends downwardly from thefitting 02 to the cross over fitting |06 which is similar to but differsslightly from the cross over fitting 30 heretofore described. Thisfitting |06 has lateral openings |01 therethrough for vreceiving thefluid flow from the openings 2 in the casing and'conducting it inwardlyto be received into the upper pumping cylinder, and similarly hasaxially extending passages I 08 for conducting flow from the lowerpumping cylinder upwardly into the annular space within the sleeve |05.

Threaded to the interior of the lower end portion of the fitting |02 isa fitting |09 which is threadedly engaged with the upper end of theupper pumping cylinder jacket H0. The space between the exterior of theupper end of the upper pumping cylinder jacket ||0 and the interior ofthe sleeve |05 provides an annular passage for the fluid from the lowerpumping cylinder. Located Within the upper pumping cylinder jacket ||0is the upper pumping cylinder liner which bears at its upper end againstthe shoulder |'|2 within the fitting |09 and at its lower end upon theshoulder ||3 within the fitting ||4 which is threaded to the lower endof the upper pumping cylinder jacket. The lower end of this fitting 4 isin turn threaded into the interior of the upper end portion of the crossover fitting |06.

The remaining structure of the pumping mechanism shown in Figs. 7, 8 and9 is identical with that heretofore described. e

' It will be s een that in this modified construction illustrated inFigs. '7, 8 and 9 it is possible to place the upper pumping cylinderjust above and immediately adjacent to the intake openings |0I 'in thecross over fitting |06, and that the position of this cross over fitting|06 may be so 'adjusted that flow comingv in from the upper producingformation will rise within the upper pumping cylinder. In order to placethe upper pumping cylinder in this relatively low position, however,r`it is necessary to provide the extra structure consisting of the sleeve|05 and the cooperating parts for conducting the iiow from the lowerpumping cylinder past the upper pumping cylinder so that it may bepassed through the interior of the packer, which in this instance islocated above the upper pumping cylinder. In all other respects, theoperation of this form of device is identical with that of the formpreviously described.

Referring now to Figs. 10, 11 and 12, there is illustrated a modifiedform which may be used in place of the arrangement for the lower pumpingcylinder and its related parts as the same were illustrated in Figs. 4,and 6.

In this modication, the parts are the same and operate in the same'manner down to the coupling 45a shown in Fig. 5. Instead of thiscoupling, the modied form referred to includes as shown in Fig. 11 acoupling 20|. Ifhis coupling is not intended to receive a packingstructure such as is secured to the upper end of the lower pump cylinderin Fig. 5, but is instead provided with a downwardly facing shoulder 202adapted to abut against the upper end of a pump liner 203 for the lowerpumping cylinder jacket 204. This lower pumping cylinder Jacket isthreadedly mounted within the lower end of the coupling and is adaptedto snugly embrace the liner 203.

On its lower end, the pumping cylinder jacket isthreaded into the upperend of another special coupling 205 which is provided with an upwardlyfacing shoulder 206 adapted to abut the lower end of the lower cylinderliner 203 thus clamping the same in position.

This coupling 205 is threaded to receive a tail pipe 20'l.at its lowerend if such a pipe be desired, and intermediate its ends is providedwith an inner upwardly facing conical seat 208 which receives and seatsabase member 209 for the standing valve cage 2i0. The standing valve 2liis carried within this cage, and mounted on the upper end of the cage isa projection 2|2 with a head 2 I 3 by which the standing valve may beremoved.

The plunger and traveling valve are in substance the same as thatillustrated in Fig. 6 but instead of the plain nut which holds thetraveling valve seat in place in Fig. 6, there is a special nut 2| 4having a bayonet socket 2|5 adapted to be engaged over vthe head 2| 3 sothat the standing valve may be pulled from the well with the travelingvalve upon removal of the sucker rods.

It will be seen that by the arrangement just described every advantagecan be obtained that can be obtained with the structures shown in Figs.4, 5 and 6 with the exception that in order to replace the lower pumpcylinder jacket or liner it is necessary to pull the tubing, whereas inthe structures shown in Figs. 4,'5 and 6 the lower pump cylinder may bereplaced by merely pulling the rods. 0n the other hand, the structureshown in Figs. 10, 11 and 12 makes possible the use of a larger lowercylinder structure than would be possible with the structure shown inFigs. 4, 5 and 6.

Except as noted, the structure shown in Figs. 10, 11 and 12 will operatein the same manner as that shown in Figs. 4, 5 and 6.

Itwill be appreciated that not only may the upper end structure of thepump shown in Figs.

. 1 to 6 inclusive be replaced by the modified form of upper endstructure shown in Figs. '7, 8 and 9 so that the upper end structureshown in Figs. 7, 8 and 9 is employed in conjunction lwith the lower endstructure shown in Figs. 4, 5 and 6, but it is also possible tosubstitute the lower end structures shown in Figs. 10, 11 and 12 forthat shown in Figs. 4. 5 and 6 and thus to employ the upper endstructure shown in Figs. 1, 2 and 3 with the lower end structure shownin Figs. 10, 11 and 12. Furthermore, it is possible to replace both theupper end structure shown in Figs. 1, 2 and 3 with that shown in Figs.7, 8 and 9 and the lower end structure shown in Figs. 4, 5 and 6 Thus,the upper end structure shown in Figs. n

1, 2 and 3 will be employed in all cases where the fluid level of theupper producing formation is lhigh enough to warrant the use of such astructure because it is less expensive and more trouble free than thatshown in Figs. 7. 8 and 9, and the upper end structure shown in Figs. 7,8 and 9 will be used in all cases where the fluid level oi' the upperproducing formation is insumcient to permit the use of the structureshown in Figs. 1, 2 and `3.

Likewise, the lower end structure shown in Figs. 4, 5 and 6 will beemployed in all cases where the use of a liner of maximum size in thelower pumping cylinder is not imperative and where it may be desired tochange the effective size of the lower pumping cylinder from time totime, but where such change in size is not essential and it is notanticipated that a vast amount of wear will be encountered in the pumpliner, the cheaper structure shown in Figs. 10, 1`1 and 12 will beemployed.

While the structures shown and described have been designed for pumpingiluid from two different zones and have been referred to as twozonepumps, it is to be understood that this invention is not limitedstrictly to pumping from two zones only, but that it may be used inconjunction with other structure embodying the same or differentprinciples for pumping from any number of zones. The use of the termtwozone in this specification and the appended claims is intended onlyto refer to the fact that the invention is useful for pumping from twozones and is not intended as limiting the invention to use in situationswhere there are only two zones being pumped.

From the foregoing it will be appreciated that a means has been providedfor carrying out and accomplishing all of the objects and advantagessought by thisy invention.

Having described my invention, I claim:

1. A well pump adapted to be disposed in a well casing and comprisingtwo cylinders in substantially axial alignment with each other, a hollowpump plunger in each cylinder, said plungers having travelling valvesfor controlling flow of fluid therethrough, an operating rod for thelower plunger interconnecting said plungers, means sealing the upper endof said lower cylinder about said rod, means providing lateral intakeopenings for said upper cylinder at a 1ocation between the two cylindersand a passageway for conducting iiuid from the upper end of said lowercylinder above the plunger therein past said intake openings, a packerabove and a' packer below said lateral intake openings for formingspaced seals between the pump and a well casing, and conduit means forconducting iluid from the passageway from the lower cylinder through theupper packerand exteriorly of the upper cylinder.

2. A well pump adapted to be disposed in a well casing and comprisingtwo cylinders in substantially axial alignment with each other, aplunger in each cylinder, an operating rod for the lower plungerinterconnecting said plungers,

ll means sealing the upper end of said lower cylinder about said rod,means providing lateral intake openings for said upper cylinder at. alof\v ,y upper cylinder, and conduit means for conducting iluid from thepassageway from the lower cylinder through the upper packer andexteriorly ofthe upper cylinder.

3. A well pump adapted to be disposed in a well casing andbomprising twocylinders in substantially axial alignment with each other, a plunger ineach cylinder; an operating rod for the lower plunger interconnectingsaid plungers, means sealing the upper end of said lower cylinder aboutsaid rod, means providing lateral intake openings for said uppercylinder at a location between the two cylinders and a passageway forconducting iluid from the upper end of said lower cylinder past saidintake openings, a packer above and a packer below said lateral intakeopenings for forming spaced seals between the pump and a well casing,the upper of said packers being located above the upper end of the uppercylinder, and conduit means for conducting fluid from the passagewayfrom the lower cylinder through the upper packer and exteriorly of theupper cylinder.

4. A two-zone well pump comprising upper and lower pumping cylinders, aplunger reciprocable in each cylinder, a rod interconnecting saidplungers, said lower cylinder having an intake opening at its lower end,a standing valve in said opening, means mechanically interconnectingsaid cylinders and providing a. lateral opening into the lower end oftheuppe'r cylinder and a longitudinal passageway from the upper end ofthe lower cylinder past said lateral opening, a. packing assemblyforming a. seal between said rod and the upper end of the lowercylinder, an annular standing valve assembly surrounding said rod abovesaid lateral opening and spaced as a unit,l and means for positioningsaid combined packing assembly and standing rvalve-assembly between saidcylinders with the packing assembly below and thel standing valveassembly above said lateral opening.

6. A two-zone well pump comprising upper and lower 'pumping cylinders. aplunger reciprocable in each cylinder, a rod interconnecting said,plungers, said lower cylinder lhaving an intake opening at its lowerend, a standing valve in said opening, means mechanicallyinterconnecting said cylinders and providing a lateral opening into thelower end oi the upper cylinder and a longitudinal passageway from theupper end of the lower cylinder past said lateral opening, a packingassembly forming a seal between said rod and the upper end of the lowercylinder, an annular standing valve assembly surrounding said rod abovesaid lateral opening and spaced from said packing vto-provide an intakevalve for the upper cylinder and means mechanically interconnecting saidpacking assembly and annular standing valve assembly to space them apartby a predetermined distance and form them into a combined unitaryassembly, said combined packing assembly and standing valve assemblybeing removable upwardly through the upper cylinder as a unit, and meansfor positioning said combined packing assembly and standing valve fromsaid packing assembly to provide an intake valve for the upper cylinder,and means mechanically interconnecting said packing assembly and annularstanding valve assembly to space them apart by a predetermined distanceand form them into a combined unitary assembly.

5. A two-zone Well pump comprising upper and lower pumping cylinders, aplunger reciprocable in each cylinder, a rod interconnecting saidplungers, said lower cylinder having an intake opening at its lower end,a standing valve in said opening, means mechanically interconnectingsaid cylinders and providing a lateral opening into the lower end of theupper cylinder and a longitudinal passageway from the upper end of thelower cylinder past said lateral opening, a'packing assembly forming aseal between said rod and the upper end of the lower cylinder, anannular standing valve assembly surrounding said rod above said lateralopening and spaced from said packing assembly to provide an intake valvefor the upper cylinder, and means mechanically interconnecting saidpacking assembly and annular standing valve assembly to space them apartby a predetermined distance and form them into a combined unitaryassembly, said combined packing assembly and standing valve assemblybeing removable upwardly through the upper cylinder,

assembly between said cylinders with the packing assembly below and thestanding valve assembly above said lateral opening, said positioningmeans including downwardly extending resilient spaced ngers on saidcombined unitary assembly, said fingers having radially outwardlyprojecting portions and downwardly and inwardly inclined lowenjendportions and being biasedto a 'normally expanded position with vrespect'to 'each .other,'. and retracting means. on

said rod below said positioning means adapted,

when said rod'is vpulled upwardly to engage the exteriors of saidinclined portions and move said fingers inwardly to a retracted positionto release the positioning means.

7. A two-zone well pump comprising upper and lower pumping cylinders, aplunger reciprocable in each cylinder, a rod interconnecting lan annularstanding valve assembly surrounding said rod above said lateral openingand spaced from said packing assembly to provide an intake valve for theupper cylinder and means mechanically interconnecting said packingassembly and annular standing valve assembly to space them apart by apredetermined distance and from them into a combined unitary assembly,said combined packing assembly and standing valve assembly beingremovable upwardly through the upper cylinder as a unit, and means forpositioning said combined packing assembly and standing valve assemblybetween said cylinders with the packing assembly below and the standingvalve assembly above said lateral opening, said positioning meansincluding downwardly extending resilient spaced fingers on said combinedunitary assembly, said fingers having radially outwardly projectingportions and downwardly and inatrasos wardly' inclined lower endportionsw and being biased to a normally expanded position with respectto each other, retracting means on said rodPL 1 downward movement of thepacker and standing valve assembly into position.

8. A two-zone pump for use in a well casing or the like comprising upperand lower substantially axially aligned cylinders, means mechanicallyinterconnecting said cylinders in spaced relation to each other andproviding a lateral opening for iluid to the lower end of the uppercylinder and a longitudinal passage for fluid from the upper end of thelower cylinder past said lateral opening to a position above the lateralopening and exteriorly of the upper cylinder, said lower cylinder havingan intake opening at its lower end, a standing valve at the lower end ofthe lower cylinder and an -annular standing valve between said lateralopening and the lower end of the upper cylinder, a combined hollowplunger and traveling valve in each cylinder, a rod interconnecting saidhollow plungers, a packing surrounding said rod and forming a sealbetween the rod and the upper end of the lower cylinder, packers forproviding a seal about the pump within a well casing above and belowsaid lateral opening respectively,

and means for conducting fluid discharged from the upper end of saidlower cylinder past said upper packer and into the annular spacesurrounding the upper cylinder.

9. A two-zone well pump for use in a well casing or the like comprisinga pair of substantially axially aligned cylinders, a plunger in eachcylinder, a rod connecting said plungers, a packing providing a sealbetween said rod and the upper end of the lower cylinder, an annularstanding valve spaced above said packing for controlling ilow into theupper cylinder, means mechanically interconnecting the cylinders andproviding a lateral opening between said packing and standing valve forilow into the upper cylinder, a standing valve carried by the lower endof said lower cylinder for controlling iniiow into the lower end of saidlower cylinder, said standing valves, lower cylinder, and packing beingremovable upwardly through said upper cylinder, and means carried bysaid rod for engaging said lower cylinder, packing and standing valvesto remove them through said upper cylinder upon upward movement beyondthe normal pumping travel of said rod.

10. A two-zone well pump for use in a wel-l casing or the likecomprising a pair of substantially axially aligned cylinders, a plungerin each cylinder, a rod connecting said plungers, a packing yproviding aseal between said rod and the upper end of the lower cylinder, anannular standing valve spaced above said packing for controlling flowinto the upper cylinder, means mechanically interconnecting thecylinders and providing a lateral opening between said packing andstanding valve for iiow into the -upper cylinder, said lstanding valve,lower cylinder, and packing being removable upwardly through said uppercylinder, and means carried by said rod for engaging said lowercylinder, packing, and standing valve to remove them through said uppercylinder upon upward movement beyond the normal pumping travel of saidrod.

11. In a two-zone pump for use in a well casing or the like, a pair oisubstantially axially aligned pumps each comprising a pumping cylinderhaving an intake opening adjacent its lower end and a discharge openingadjacent its upper end, a standing valve in each intake opening, ahollow plunger and traveling valve in each cylinder, a rod connectingsaid plungers, a packing providing a seal between said rod and the upperend of the lower cylinder, said rod, packing, and plunger in the lowercylinder being removable upwardly through the upper cylinder, meansmechanically connecting said two cylinders to provide a unitaryassembly, a tubing connected to the outlet of said upper cylinder, aconduit connected to the outlet of said lower cylinder and discharginginto the space surrounding said tubing, and spaced packers surroundingsaid assembly above and below the intake for said upper cylinderrespectively.

12. A two-zonepump for use in well casings or the like comprising a pairof substantially axially aligned cylinders. a plunger in each cylinder,a rod connecting said plungers, a packing providing a seal between thesaid rod and the upper end of the lower cylinder, a standing valvecarried by the lower end of said lower cylinder for controlling inflowinto the lower end of said lower cylinder, said standing valve, lowercylinder and packing being removable upwardly through said uppercylinder, and means carried bysaid rod for engaging said lower cylinder,packing and standing valve to remove them through said upper cylinderupon upward movement beyond the normal pumping travel of said rod.

13. A two-zone well pump for use in a well casing or the like comprisinga pair of substantially axially aligned cylinders, a plunger in eachcylinder, a rod' connecting said plungers, a packing providing a sealbetween said rod and the upper endv of the lower cylinder, a standingvalve spaced-f above said packing for controlling ow into the uppercylinder, a second standing valve adjacent the lower end of the lowercylinder for controlling flow into the lower cylinder, meansmechanically interconnecting the cylinders and providing a lateralopening between said packing and iirst standing valve for flow into theupper cylinder, said second standing valve, lower cylinder and packingbeing removable upwardly through said upper cylinder, means carried bysaid rod for engaging said lower cylinder, packing and said secondstanding valve to remove them through said upper cylinder upon upwardmovement beyond the normal pumping travel of said rod, a packer aboveand packer below said lateral intake opening for forming spaced sealsbetween the pump and a well casing, the upper of said packers beinglocated below the lower end of the upper cylinder, and conduit means forconducting iiuid from the lower cylinder through the upper packer to thespace exteriorly of the upper cylinder.

14. A two-zone well pump for use in a well casing or the like comprisinga pair of substantially axially aligned cylinders, a plunger in eachcylinder, a rod connecting said plungers, a packing providing a sealbetween said rod and the upper end of the lower cylinder, a standingvalve spaced above said packing for controlling flow into the uppercylinder, a second standing valve adjacent the lower end of the lowercylinder for controlling iiow into the lower cylinder, meansmechanically interconnecting the cylinders and providing a lateralopening between said packing and first standing valve for flow into theupper cylinder, said second standing valve, lower cylinder nasce andpacking being removable upwardly through said upper cylinder, meanscarried by said rod for engaging said lower cylinder, packing and saidsecond standing valve to remove them through said upper cylinder uponupward movement be` rod connecting said plungers, a packing providing aseal between the said rod and the upper end of i6 the lower cylinder. astanding valve carried by the lower end oi said lower cylinder vforcontrolling inflow into thek lower end of said lower cylinder, saidstanding valve and packing being removable upwardly through said uppercylinder, and means carried by said rod for engaging said packing andstanding valve to remove them through said upper cylinder upon upwardmovement of the rod beg yond the normal pumping travel of said rod.

5 A TEMPLE P. HOFFER.

` REFERENJCES cr'ran l The following references are of record in theille oi this patent:

UNITED STATES PATENTS Number Name Date 2,281,899 White May 5, 1942

